This invention relates to external infusion devices and, in particular embodiments to external infusion devices that control the rate that a fluid is infused into an individual""s body.
Portable personal infusion devices and systems are relatively well-known in the medical arts, for use in delivering or dispensing a prescribed medication to a patient. Many pharmaceutical agents are delivered into the subcutaneous tissue and the most common is insulin. Currently, more than 70,000 patients in the U.S. and 30,000 more patients worldwide use continuous subcutaneous infusion of insulin (CSII) for the treatment of diabetes mellitus. However, other medications that are infused include HIV drugs, drugs to treat pulmonary hypertension, iron chelation drugs, pain medications, and anti-cancer treatments.
Traditionally, low cost infusion devices have used an elastomeric diaphragm, sponge rubber, balloon or gas generator to expel fluid to be infused into a patient over a period of time at a single, relatively constant rate. A drawback to these devices is that they are only filled with fluid once. When the infusion of fluid is complete, the infusion device is disposed of. Thus, the infusion device must be made at an extremely low cost. Another drawback is that the low cost may not allow for the high quality needed to have sufficient flow rate control accuracy for the delivery of dosage sensitive drugs.
To obviate these drawbacks, infusion devices have been designed with more accurate dosage control, but at a significantly higher cost. To compensate for the relatively high cost, the more accurate infusion devices are designed to be refilled and reused.
In one form, refillable infusion devices comprise a relatively compact housing adapted to receive a syringe or reservoir carrying a prescribed medication for administration to the patient through infusion tubing and an associated catheter or infusion set. Such infusion devices are utilized to administer insulin and other medications, with exemplary infusion device constructions being shown and described in U.S. Pat. Nos. 4,562,751; 4,678,408; 4,685,903; 5,080,653 and 5,097,122, which are incorporated by reference herein.
While the sophisticated electronics and robust mechanics of the more expensive refillable infusion devices provide a more reliable and accurate infusion device, the cost of manufacturing may make the refillable infusion device too expensive for some users or medications. On the other hand, the low cost, one-time-use, constant flow rate infusion devices may not have sufficient flow rate accuracy or the adjustments needed to control the dosage for some users.
According to an embodiment of the invention, a reusable external infusion device with a predetermined usage life for infusing a fluid into a body includes a replaceable reservoir, a power supply, a drive system, an electronics system, and a housing. The housing contains the reservoir, power supply, drive system and electronics system. The replaceable reservoir contains the fluid before infusing and has a usage life substantially shorter than the predetermined usage life of the infusion device. The power supply provides power to the drive system and the electronics system to force fluid from the reservoir. The electronics system regulates the power from the power supply to control the drive system.
In particular embodiments of the present invention, the infusion device includes a control system operatively coupled to the electronics system that adjusts one or more control parameters. In more particular embodiments, the control system is a supplemental device. In additional embodiments, the supplemental device establishes two way communication with the electronics system. In particular embodiments, the supplemental device has a display.
In preferred embodiments, after the infusion device""s predetermined usage life has expired, the infusion device may be refurbished at least once to function for another predetermined usage life. In particular embodiments, when the predetermined usage life for the infusion device expires, the infusion device ceases to infuse fluid. In further particular embodiments, the predetermined usage life for the infusion device is programmed into a software program as a number of times that the replaceable reservoir is replaced in the infusion device.
In preferred embodiments, the drive mechanism of the infusion device contains a DC motor in the drive system. In alternative embodiments, the drive mechanism of the infusion device contains a stepper motor, solenoid motor, a shape memory alloy driven motor, or the like.
According to another embodiment of the present invention, a reusable external infusion device is for infusing a fluid into an individual. In preferred embodiments, the infusion device includes a housing and a replaceable fluid containing reservoir that is inserted into the housing. In preferred embodiments, the housing contains only one electronics module to control the infusion device. In particular embodiments, the electronics module contained within the housing is produced using chip-on-board construction. In other particular embodiments, the electronics module contained within the housing is produced using ball grid array construction. In further embodiments, the electronics module a flex circuit to control the infusion device. In preferred embodiments, the housing contains a detection device that detects the presence or absence of the replaceable reservoir. In further preferred embodiments, the reusable external infusion device further includes a drive mechanism coupled to an electronics system and the housing includes a button coupled to the electronics system that an individual may push to cause the drive mechanism to deliver a bolus of fluid into the individual.
In additional preferred embodiments, the housing and internal contents are assembled together without screws. In more preferred embodiments, the housing includes at least one feature that is fused using ultrasonic vibrations. In other preferred embodiments, the housing includes a drive mechanism that contains at least one non-metallic gear.
In preferred embodiments, the housing includes a slidable key that provides access to remove and/or replace the replaceable reservoir inside the housing. In particular embodiments, the housing accepts a key that includes a communication device for communicating with a supplemental device. In alternative embodiments, the housing accepts a tab that includes a communication device for communicating with a supplemental device. In further alternative embodiments, the housing accepts a tab/key that includes a communication device for communicating with a supplemental device.
In further preferred embodiments, the housing includes an opening to insert a removable tab that includes a programmable chip that contains at least one control parameter to control the infusion device. In further embodiments, the housing includes an opening to insert a tab that includes at least one electrical terminal that establishes electrical contact between at least one set of electrical terminals inside the housing. In particular embodiments, the housing is adapted to receive at least one of at least two different tabs that are insertable into the housing, and the at least two different tabs each have different electrical terminal configurations that establish electrical contact between different electrical terminals inside the housing, and connects different electrical terminals to cause the external infusion device to dispense fluid at different rates. In still further embodiments, the housing is adapted to receive at least one tab with an optically readable pattern, and the housing includes an optical reader to read the optically readable pattern on the at least one tab to control at least one control parameter of the reusable external infusion device. In alternative embodiments, the housing is adapted to receive at least one tab that includes magnetically stored information, and the housing includes a magnetic reader to read the magnetically stored information from the at least one tab to control at least one control parameter of the reusable external infusion device.
In preferred embodiments, the reusable external infusion device includes at least one lithium magnesium oxide (LiMnO2) battery. In particular embodiments, the reusable external infusion device includes a battery that lasts at least 10 weeks, measured while the reusable external infusion device dispenses up to 40 milliliters of fluid per day and while the alarms draw substantially no power from at least one battery.
In additional particular embodiments, an alarm is activated when the reusable external infusion device needs to be refurbished. In preferred embodiments, the reusable external infusion device has a predetermined usage life and when the predetermined usage life has expired, the reusable external infusion device may be refurbished at least once to function for another predetermined usage life. In particular embodiments, the reusable external infusion device has a predetermined usage life and when the predetermined usage life expires, the reusable external infusion device ceases to infuse fluid.
In further particular embodiments, the reusable external infusion device has a predetermined usage life and the predetermined usage life for the reusable external infusion device is programmed into a software program as a number of times that the replaceable reservoir is replaced in the housing, as a number of days that the reusable external infusion device is in use, as the number of times the battery is replaced in the reusable external infusion device, and/or as the number of times that a key is removed from the reusable external infusion device. In other embodiments, the reusable external infusion device has a predetermined usage life and the predetermined usage life for the reusable external infusion device is expired when the amount of electrical power consumed to empty a reservoir exceeds a predetermined amount programmed into a software program.